# -*- coding: utf-8 -*-
"""
EvMore - pager mechanism
This is a pager for displaying long texts and allows stepping up and down in
the text (the name comes from the traditional 'more' unix command).
To use, simply pass the text through the EvMore object:
```python
from evennia.utils.evmore import EvMore
text = some_long_text_output()
EvMore(caller, text, always_page=False, session=None, justify_kwargs=None, **kwargs)
```
One can also use the convenience function `msg` from this module to avoid
having to set up the `EvMenu` object manually:
```python
from evennia.utils import evmore
text = some_long_text_output()
evmore.msg(caller, text, always_page=False, session=None, justify_kwargs=None, **kwargs)
```
The `always_page` argument decides if the pager is used also if the text is not long
enough to need to scroll, `session` is used to determine which session to relay
to and `justify_kwargs` are kwargs to pass to utils.utils.justify in order to
change the formatting of the text. The remaining `**kwargs` will be passed on to
the `caller.msg()` construct every time the page is updated.
----
"""
from django.conf import settings
from django.core.paginator import Paginator
from django.db.models.query import QuerySet
from django.utils.translation import gettext as _
from evennia.commands import cmdhandler
from evennia.commands.cmdset import CmdSet
from evennia.commands.command import Command
from evennia.utils.ansi import ANSIString
from evennia.utils.utils import dedent, inherits_from, justify, make_iter
_CMD_NOMATCH = cmdhandler.CMD_NOMATCH
_CMD_NOINPUT = cmdhandler.CMD_NOINPUT
# we need to use NAWS for this
_SCREEN_WIDTH = settings.CLIENT_DEFAULT_WIDTH
_SCREEN_HEIGHT = settings.CLIENT_DEFAULT_HEIGHT
_EVTABLE = None
_LBR = ANSIString("\n")
# text
_DISPLAY = """{text}
|n(|wPage|n [{pageno}/{pagemax}] |wn|next|n || |wp|nrevious || |wt|nop || |we|nnd || |wq|nuit)"""
[docs]class CmdMore(Command):
"""
Manipulate the text paging. Catch no-input with aliases.
"""
key = _CMD_NOINPUT
aliases = ["quit", "q", "abort", "a", "next", "n", "previous", "p", "top", "t", "end", "e"]
auto_help = False
[docs] def func(self):
"""
Implement the command
"""
more = self.caller.ndb._more
if not more and hasattr(self.caller, "account"):
more = self.caller.account.ndb._more
if not more:
self.caller.msg("Error in loading the pager. Contact an admin.")
return
cmd = self.cmdstring
if cmd in ("abort", "a", "q"):
more.page_quit()
elif cmd in ("previous", "p"):
more.page_back()
elif cmd in ("top", "t", "look", "l"):
more.page_top()
elif cmd in ("end", "e"):
more.page_end()
else:
# return or n, next
more.page_next()
[docs]class CmdMoreExit(Command):
"""
Any non-more command will exit the pager.
"""
key = _CMD_NOMATCH
[docs] def func(self):
"""
Exit pager and re-fire the failed command.
"""
more = self.caller.ndb._more
more.page_quit()
# re-fire the command (in new cmdset)
self.caller.execute_cmd(self.raw_string)
[docs]class CmdSetMore(CmdSet):
"""
Stores the more command
"""
key = "more_commands"
priority = 110
mergetype = "Replace"
[docs] def at_cmdset_creation(self):
self.add(CmdMore())
self.add(CmdMoreExit())
# resources for handling queryset inputs
[docs]def queryset_maxsize(qs):
return qs.count()
[docs]class EvMore(object):
"""
The main pager object
"""
[docs] def __init__(
self,
caller,
inp,
always_page=False,
session=None,
justify=False,
justify_kwargs=None,
exit_on_lastpage=False,
exit_cmd=None,
page_formatter=str,
**kwargs,
):
"""
Initialization of the EvMore pager.
Args:
caller (Object or Account): Entity reading the text.
inp (str, EvTable, Paginator or iterator): The text or data to put under paging.
- If a string, paginage normally. If this text contains
one or more `\\\\f` format symbol, automatic pagination and justification
are force-disabled and page-breaks will only happen after each `\\\\f`.
- If `EvTable`, the EvTable will be paginated with the same
setting on each page if it is too long. The table
decorations will be considered in the size of the page.
- Otherwise `inp` is converted to an iterator, where each step is
expected to be a line in the final display. Each line
will be run through `iter_callable`.
always_page (bool, optional): If `False`, the
pager will only kick in if `inp` is too big
to fit the screen.
session (Session, optional): If given, this session will be used
to determine the screen width and will receive all output.
justify (bool, optional): If set, auto-justify long lines. This must be turned
off for fixed-width or formatted output, like tables. It's force-disabled
if `inp` is an EvTable.
justify_kwargs (dict, optional): Keywords for the justify function. Used only
if `justify` is True. If this is not set, default arguments will be used.
exit_on_lastpage (bool, optional): If reaching the last page without the
page being completely filled, exit pager immediately. If unset,
another move forward is required to exit. If set, the pager
exit message will not be shown.
exit_cmd (str, optional): If given, this command-string will be executed on
the caller when the more page exits. Note that this will be using whatever
cmdset the user had *before* the evmore pager was activated (so none of
the evmore commands will be available when this is run).
kwargs (any, optional): These will be passed on to the `caller.msg` method.
Examples:
```python
super_long_text = " ... "
EvMore(caller, super_long_text)
```
Paginator
```python
from django.core.paginator import Paginator
query = ObjectDB.objects.all()
pages = Paginator(query, 10) # 10 objs per page
EvMore(caller, pages)
```
Every page an EvTable
```python
from evennia import EvTable
def _to_evtable(page):
table = ... # convert page to a table
return EvTable(*headers, table=table, ...)
EvMore(caller, pages, page_formatter=_to_evtable)
```
"""
self._caller = caller
self._always_page = always_page
if not session:
# if not supplied, use the first session to
# determine screen size
sessions = caller.sessions.get()
if not sessions:
return
session = sessions[0]
self._session = session
self._justify = justify
self._justify_kwargs = justify_kwargs
self.exit_on_lastpage = exit_on_lastpage
self.exit_cmd = exit_cmd
self._exit_msg = _("|xExited pager.|n")
self._kwargs = kwargs
self._data = None
self._pages = []
self._npos = 0
self._npages = 1
self._paginator = self.paginator_index
self._page_formatter = str
# set up individual pages for different sessions
height = max(4, session.protocol_flags.get("SCREENHEIGHT", {0: _SCREEN_HEIGHT})[0] - 4)
self.width = session.protocol_flags.get("SCREENWIDTH", {0: _SCREEN_WIDTH})[0]
# always limit number of chars to 10 000 per page
self.height = min(10000 // max(1, self.width), height)
# does initial parsing of input
self.init_pages(inp)
# kick things into gear
self.start()
# EvMore functional methods
[docs] def display(self, show_footer=True):
"""
Pretty-print the page.
"""
pos = 0
text = "[no content]"
if self._npages > 0:
pos = self._npos
text = self.page_formatter(self.paginator(pos))
if show_footer:
page = _DISPLAY.format(text=text, pageno=pos + 1, pagemax=self._npages)
else:
page = text
# check to make sure our session is still valid
sessions = self._caller.sessions.get()
if not sessions:
self.page_quit()
return
# this must be an 'is', not == check
if not any(ses for ses in sessions if self._session is ses):
self._session = sessions[0]
self._caller.msg(text=page, session=self._session, **self._kwargs)
[docs] def page_top(self):
"""
Display the top page
"""
self._npos = 0
self.display()
[docs] def page_end(self):
"""
Display the bottom page.
"""
self._npos = self._npages - 1
self.display()
[docs] def page_next(self):
"""
Scroll the text to the next page. Quit if already at the end
of the page.
"""
if self._npos >= self._npages - 1:
# exit if we are already at the end
self.page_quit()
else:
self._npos += 1
if self.exit_on_lastpage and self._npos >= (self._npages - 1):
self.display(show_footer=False)
self.page_quit(quiet=True)
else:
self.display()
[docs] def page_back(self):
"""
Scroll the text back up, at the most to the top.
"""
self._npos = max(0, self._npos - 1)
self.display()
[docs] def page_quit(self, quiet=False):
"""
Quit the pager
"""
del self._caller.ndb._more
if not quiet:
self._caller.msg(text=self._exit_msg, **self._kwargs)
self._caller.cmdset.remove(CmdSetMore)
if self.exit_cmd:
self._caller.execute_cmd(self.exit_cmd, session=self._session)
[docs] def start(self):
"""
Starts the pagination
"""
if self._npages <= 1 and not self._always_page:
# no need for paging; just pass-through.
self.display(show_footer=False)
else:
# go into paging mode
# first pass on the msg kwargs
self._caller.ndb._more = self
self._caller.cmdset.add(CmdSetMore)
# goto top of the text
self.page_top()
# default paginators - responsible for extracting a specific page number
[docs] def paginator_index(self, pageno):
"""Paginate to specific, known index"""
return self._data[pageno]
[docs] def paginator_slice(self, pageno):
"""
Paginate by slice. This is done with an eye on memory efficiency (usually for
querysets); to avoid fetching all objects at the same time.
"""
return self._data[pageno * self.height : pageno * self.height + self.height]
[docs] def paginator_django(self, pageno):
"""
Paginate using the django queryset Paginator API. Note that his is indexed from 1.
"""
return self._data.page(pageno + 1)
# default helpers to set up particular input types
[docs] def init_evtable(self, table):
"""The input is an EvTable."""
if table.height:
# enforced height of each paged table, plus space for evmore extras
self.height = table.height - 4
# convert table to string
text = str(table)
self._justify = False
self._justify_kwargs = None # enforce
self.init_str(text)
[docs] def init_queryset(self, qs):
"""The input is a queryset"""
nsize = qs.count() # we assume each will be a line
self._npages = nsize // self.height + (0 if nsize % self.height == 0 else 1)
self._data = qs
[docs] def init_django_paginator(self, pages):
"""
The input is a django Paginator object.
"""
self._npages = pages.num_pages
self._data = pages
[docs] def init_iterable(self, inp):
"""The input is something other than a string - convert to iterable of strings"""
inp = make_iter(inp)
nsize = len(inp)
self._npages = nsize // self.height + (0 if nsize % self.height == 0 else 1)
self._data = inp
[docs] def init_f_str(self, text):
"""
The input contains `\\f` markers. We use `\\f` to indicate the user wants to
enforce their line breaks on their own. If so, we do no automatic
line-breaking/justification at all.
Args:
text (str): The string to format with f-markers.
"""
self._data = text.split("\f")
self._npages = len(self._data)
[docs] def init_str(self, text):
"""The input is a string"""
if self._justify:
# we must break very long lines into multiple ones. Note that this
# will also remove spurious whitespace.
justify_kwargs = self._justify_kwargs or {}
width = self._justify_kwargs.get("width", self.width)
justify_kwargs["width"] = width
justify_kwargs["align"] = self._justify_kwargs.get("align", "l")
justify_kwargs["indent"] = self._justify_kwargs.get("indent", 0)
lines = []
for line in text.split("\n"):
if len(line) > width:
lines.extend(justify(line, **justify_kwargs).split("\n"))
else:
lines.append(line)
else:
# no justification. Simple division by line
lines = text.split("\n")
self._data = [
_LBR.join(lines[i : i + self.height]) for i in range(0, len(lines), self.height)
]
self._npages = len(self._data)
# Hooks for customizing input handling and formatting (override in a child class)
[docs] def init_pages(self, inp):
"""
Initialize the pagination. By default, will analyze input type to determine
how pagination automatically.
Args:
inp (any): Incoming data to be paginated. By default, handles pagination of
strings, querysets, django.Paginator, EvTables and any iterables with strings.
Notes:
If overridden, this method must perform the following actions:
- read and re-store `self._data` (the incoming data set) if needed for pagination to
work.
- set `self._npages` to the total number of pages. Default is 1.
- set `self._paginator` to a callable that will take a page number 1...N and return
the data to display on that page (not any decorations or next/prev buttons). If only
wanting to change the paginator, override `self.paginator` instead.
- set `self._page_formatter` to a callable that will receive the page from
`self._paginator` and format it with one element per line. Default is `str`. Or
override `self.page_formatter` directly instead.
By default, helper methods are called that perform these actions
depending on supported inputs.
"""
if inherits_from(inp, "evennia.utils.evtable.EvTable"):
# an EvTable
self.init_evtable(inp)
self._paginator = self.paginator_index
elif isinstance(inp, QuerySet):
# a queryset
self.init_queryset(inp)
self._paginator = self.paginator_slice
elif isinstance(inp, Paginator):
self.init_django_paginator(inp)
self._paginator = self.paginator_django
elif not isinstance(inp, str):
# anything else not a str
self.init_iterable(inp)
self._paginator = self.paginator_slice
elif "\f" in inp:
# string with \f line-break markers in it
self.init_f_str(inp)
self._paginator = self.paginator_index
else:
# a string
self.init_str(inp)
self._paginator = self.paginator_index
[docs] def paginator(self, pageno):
"""
Paginator. The data operated upon is in `self._data`.
Args:
pageno (int): The page number to view, from 0...N-1
Returns:
str: The page to display (without any decorations, those are added
by EvMore).
"""
return self._paginator(pageno)
[docs] def page_formatter(self, page):
"""
Page formatter. Every page passes through this method. Override
it to customize behavior per-page. A common use is to generate a new
EvTable for every page (this is more efficient than to generate one huge
EvTable across many pages and feed it into EvMore all at once).
Args:
page (any): A piece of data representing one page to display. This must
Returns:
str: A ready-formatted page to display. Extra footer with help about
switching to the next/prev page will be added automatically
"""
return self._page_formatter(page)
# helper function
[docs]def msg(
caller,
text="",
always_page=False,
session=None,
justify=False,
justify_kwargs=None,
exit_on_lastpage=True,
**kwargs,
):
"""
EvMore-supported version of msg, mimicking the normal msg method.
"""
EvMore(
caller,
text,
always_page=always_page,
session=session,
justify=justify,
justify_kwargs=justify_kwargs,
exit_on_lastpage=exit_on_lastpage,
**kwargs,
)
msg.__doc__ += dedent(EvMore.__init__.__doc__)
